§ 21.127. Shellac (refined).
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/us/cfr/t27/s§ 21.127·A research copy — for the controlling text, always check the official state or federal source. Not legal advice.
(a)Arsenic content. Not more than 1.4 parts per million as determined by the Gutzeit Method (AOAC method 25.020; for incorporation by reference, see § 21.6(c)).
(b)Color. White or orange.
(c)Rosin content. None when tested by the following method: Add 20 mL of absolute alcohol or glacial acetic acid (m. p. 13° to 15 °C.) to 2 grams of the shellac and thoroughly dissolve. Add 100 mL of petroleum ether and mix thoroughly. Add approximately 2 liters of water and separate a portion of the ether layer (at least 50 mL) and filter if cloudy. Evaporate the petroleum ether and test as follows: Solution A---5 mL of phenol dissolved in 10 mL of carbon tetrachloride. Solution B---1 mL of bromine dissolved in 4 mL of carbon tetrachloride. To the residue obtained above add 2 mL of Solution A and transfer the mixture to a porcelain spot plate, filling one cavity. Immediately fill an adjacent cavity with solution B. Cover the plate with a watch glass and observe any color formation in Solution A. A decided purple or deep indigo blue color is an indication of the presence of rosin. \[T.D. ATF-133, 48 FR 24673, June 2, 1983. Redesignated by T.D. ATF-442, 66 FR 12854, Mar. 1, 2001\]